The present invention relates to a gas turbine engine, and more particularly to a rotational flow balance system controlled by a single actuator system to satisfy operational requirements of the gas turbine engine while providing inherent benefits of semi-coupling together two or more flow control components.
In current gas turbine engine exhaust ducts, a liner is disposed between the engine exhaust gas path and the engine outer casing or duct. Cooling air is flowed between the cooling liner and duct then discharged over the seals and flaps of the nozzle located at the rear end of the exhaust duct. In order to improve engine operation and performance, exhaust duct cooling air is carefully rationed. Since cooling air extracted from the engine may then not be utilized for producing thrust, this extracted cooling air may be a penalty to the overall performance of the engine.
To control the quantity of cooling airflow while the engine is subjected to large core pressure gradients at various operating conditions, a rotational flow balance system includes a rotatable control member that is rotated to control the cooling airflow. A multiple of rotational flow balance systems facilitate control of the quantity of cooling airflow during multi-cycle operation of the gas turbine engine. Although effective, each rotational flow balance system typically includes a separate actuation system which generally increases engine weight and complexity.
Accordingly, it is desirable to provide a rotational flow balance system with a multiple of rotational components which are controlled by a single actuator system.